Okay I'am still at it seeing if there is much difference between old and newer. The biggest number that is the surprise is the turning radius between the older leaf sprung F450/550 with a 165 wheelbase trucks to todays F-450/550 with the same wheelbase. A 99-04 the turning radius is 59.4 feet the turning radius of a 05-current is 48.8 a difference of 10.6 feet that is quite abit. I don't live in the city so turning in city streets not a problem for me. My current truck makes the corners and turns that I need to make with not too many problems. Brakes the newer trucks don't have very much size difference in brakes so a 05 and newer truck I'am not going to see anymore braking power. Same rotor sizes little different brake pads. I thought the newer truck used larger brakes but they do not. Rear springs the 05 and newer F-450s have 680lb more capacity than a 03 F450. The 05 and newer 550 has 518lbs more capacity than a 03 F-550. The long story of it is the only difference between the 05 and newer trucks with coil springs is the better turning radius. On a 4x4 truck the tighter turning radius must be a killer on the axle U joints with the wheel turned that sharp. The only benefit of buying a newer truck is having a newer truck so I will end up buying the 03 F-550 4x4. If the 4R100 needs a rebuild I will rebuild it. Not really enough benefits to justify spending 10 grand more for a 2007.